Though widespread, Carex crawei is usually rare or local except near the shores of the Great Lakes, glades in the Interior Highlands, and prairie swales on parts of the Great Plains. Other authors have reported it from Nova Scotia (H. J. Scoggan 1978–1979, part 2; earlier mentioned by M. L. Fernald 1948 on the authority of J. M. Macoun 1899); no specimens to substantiate the reports have been found.

The perigynia in Carex crawei are usually smaller than in C. microdonta. A few specimens from Ontario and New York with all other characteristics of C. crawei have larger and slightly beaked perigynia that approach those of C. microdonta.